摘要:
A dividing wall column comprises the following segments:a) an upper column region (1),b) an enrichment section (2) of the feed section,c) a stripping section (4) of the feed section,d) an upper part (3) of the offtake section,e) a lower part (5) of the offtake section,f) an intermediate region (9) of the feed section,g) an intermediate region (10) of the offtake section andh) a lower column region (6).For the purposes of the present invention, it is essential that the dividing wall (7) is located vertically between the segments b) (2) and d) (3) and between the segments c) (4) and e) (5), the segments b) (2), d) (3), c) (4) and e) (5) have separation-active internals and the cross-sectional area Ab of the segment b) (2) is at least 10% smaller than the cross-sectional area Ad of segment d) (3), and the cross-sectional area Ac of the segment c) (4) is at least 10% greater than the cross-sectional area Ae of segment e) (5).
摘要:
A dividing wall column is described which includes the following segments:a) an upper column region (1),b) an enrichment section (2) of the feed section,c) a stripping section (4) of the feed section,d) an upper part (3) of the offtake section,e) a lower part (5) of the offtake section,f) an intermediate region (9) of the feed section,g) an intermediate region (10) of the offtake section andh) a lower column region (6).The dividing wall column has a dividing wall (7) is located vertically between the segments b) (2) and d) (3) and between the segments c) (4) and e) (5). The segments b) (2), d) (3), c) (4) and e) (5) have separation-active internals, Segment b (2) has a cross-sectional area Ab which is at least 10% smaller than the cross-sectional area Ad of segment d) (3), and segment c) has a cross-sectional area Ac which is at least 10% greater than the cross-sectional area Ae of segment e) (5).
摘要:
A process for preparing alkali metal salts of L-ascorbic acid comprising the following steps: a) esterifying 2-keto-L-gulonic acid or diacetone-2-keto-L-gulonic acid with a C1-C10-alkohol in the presence of an acid catalyst, b) rearranging the resultant 2-keto-L-gulonic acid C1-C10-alkyl ester in the presence of an alkali metal C1-C10-alkoxide, comprises carrying out each of the process steps a) and b) continuously.
摘要:
Organic iodine compounds are separated from carbonylation products of methanol, methyl acetate and dimethyl ether and from mixtures of such carbonylation products by a process wherein the iodine compounds are removed by liquid phase extraction with a non-aromatic hydrocarbon.
摘要:
A process is provided wherein acetaldehyde and methanol are obtained from reaction mixtures which result from the homologization of methanol and which in addition to acetaldehyde essentially contain acetaldehyde dimethylacetal, methanol, methyl acetate and water.
摘要:
Liquid mixtures containing aliphatic alcohols are separated, by distillation, into a higher-boiling alcohol-containing fraction and a lower-boiling fraction containing the other liquids, by carrying out the fractionation in the presence of water and of an alkanal and, over about 3/4 of the column height, in the presence of a non-volatile or only slightly volatile acid.
摘要:
Formic acid is recovered, by distillation, from its mixtures with solvents of the general formula I ##STR1## where R.sup.1 is hydrogen, methyl, ethyl or vinyl and R.sup.2 and R.sup.3 are each alkyl, cycloalkyl, aryl or aralkyl, or R.sup.2 and R.sup.3 together form a 1,4- or 1,5-alkylene group, in each case of not more than 8 carbon atoms, with the provisos that the sum of the number of carbon atoms in R.sup.2 and R.sup.3 is 7 to 14 and that only one of these radicals is aryl, by a method in which the distillation is carried out in the presence of a carboxamide II which is selected from the group consisting of formamide, acetamide, propionamide and the same compounds substituted by N-methyl or N,N-dimethyl, and which has a boiling point lower than that of the solvent I.
摘要:
A process for separating off organic iodine compounds from acetaldehyde by subjecting the acetaldehyde to azeotropic distillation with a hydrocarbon boiling at from 25.degree. to 55.degree. C. under atmospheric pressure.
摘要:
A process for separating off organic iodine compounds from acetaldehyde-free carbonylation products of methanol, methyl acetate and dimethyl ether by removing the iodine compounds by azeotropic distillation with a hydrocarbon having a boiling point, under atmospheric pressure, of 25-55.degree. C.
摘要:
Apparatus and processes for continuous distillative separation of a mixture comprising one or more alkanolamine(s) are described. The separation is performed in one or more dividing wall column(s) and the alkanolamine or the alkanolamines is/are withdrawn as a side draw stream or side draw streams (side fraction(s)).